Coal ash utilization technologies in Japan

Japan is one of the major coal-importing countries in the world, importing more than 100 types of coal every year, with some of the electric power utilities using as many as 20 to 40 types of coal per year. Japan's dependency on coal is expected to still increase in future, under the measure to diversify energy resources in our country. In order to use the coal stably, it is important to expand effective use of the coal as well as to use coal cleanly and effectively. Although our country uses coal ash for cement raw material, concrete admixture, earth filling, etc., it is required to develop technologies to effective use large amounts of coal ash. The paper describes here the situation of coal ash production and the trend of the utilization technologies development in Japan. 4 refs., 5 figs., 9 tabs.